1. Field of the invention
The present invention relates to starters and, more particularly, to a starter with an intermediate gear adapted to remain in meshing engagement with a pinion gear at all times and operative to be brought into meshing engagement with a ring gear of an engine to perform startup of the engine.
2. Description of the Related Art
An attempt has been made in the related art to provide a starter with an intermediate gear as disclosed in U.S. Pat. No. 5,265,485.
With the starter of such a related art, a housing has through-bores to which both ends of an intermediate shaft are inserted to be supported. The intermediate shaft carries thereon an axially movable intermediate gear with which a pinion gear is held in meshing engagement at all times. During startup of an engine, the intermediate gear is axially moved together with the pinion gear into meshing engagement with a ring gear of the engine.
The intermediate shaft has a rear end coupled to a retainer through which the intermediate shaft is retained to the housing. The retainer has a polygonal shape in cross section and is inserted to a polygonal aperture, formed in the housing, to be fixedly retained.
However, due to a structure wherein the intermediate shaft is inserted to the through-bore from a rear side (at an area closer to the motor) of the housing during assembly, a difficulty is encountered in assembling the intermediate shaft after a yoke of the motor has been fixedly secured to the housing. Accordingly, a need arises for assembling the intermediate shaft before the yoke is assembled to the housing.
Further, the yoke of the motor is employed as a stopper to prevent the retainer, inserted to the polygonal aperture, from dropping off the housing. That is, when the retainer is inserted to the polygonal aperture after which the motor is fixedly mounted to the housing, a front end of the yoke is brought into abutting engagement with the retainer, enabling the retainer to be prevented from dropping off.
With such a structure set forth above, the intermediate shaft and the retainer necessarily need to be assembled before the yoke is fixedly mounted to the housing with the resultant deterioration in assembling capability. Moreover, under circumstances where the yoke is fixedly secured to the housing, the intermediate shaft is hard to be attached to or detached from the housing. Thus, if a need arises for the intermediate gear to be replaced, the yoke is removed from the housing after which the yoke needs to be assembled to the housing again, resulting in extremely deteriorated assembling capability.